Manufacture of artificial silk



March' 13, 1934. F. H. GRIFFIN MANUFACTUBE OF ARTIFICIAL SILK 3Sheets-Sheet 1 Filed April 26, 1927 l/V VE N TOR Ma'rch 13, 1934. F H,GRIFHN 1,950,922

' MANUFAGTURE 0F ARTIFICIAL SILK Filed April 28, 1927 3 SheebS--Sheei'l2 March 13,1934. F` H, GRIFFIN l 1,950,922

MANUFAGTURE OF ARTIFICIAL SILK Filed April 26, 1927 5 Sheets-Sheet 3 lINVENTOI? HT-ranf/EK;

Patented Mar. v13, 1934 PATENT OFFICE 1,950,922 MANUFACTURE orARTIFICIAL SILK Frank H. Griffin, Wawa, Pa., assignor to The ViscoseCompany, Marcus Hook, Pa., a corporation of Pennsylvania ApplicationApril 26, 1927, Serial No. 186,728

17 Claims.

My invention relates to the manufacture of artificial silk', andparticularly to an improvement in method and apparatus by which theproduct is improved from the standpoint of vtensile strength, uniformityin strength and size, and dyeing properties. While my invention may beapplicable to dry spinning as well as wet spinning, and also to silkspun from various cellulosic solutions, I have practiced it particularlyin the manufacture of artificial silk from viscose, and accordingly haveillustrated viscose silk spinningl apparatusin the accompanying more orless diagrammatic drawings, in which Fig. 1 is a side elevation,partially in section,

15 of la viscose spinning unit adapted for the practice of my invention;

. Fig. 2 is an enlarged section illustrating the adjustable carrier barinfwhich a-,battery of lower godets and their associated guides aremounted;

Fig. 3 is a broken plan view of portion of a battery of spinning units,only the pumps and lower godets and their drive connections being shown;

Fig. 4 is an end elevation of the drive gear for the lower godets andpumps;

Fig. 5 is a front elevation of the spinning unit' shown in Fig. 1;

Fig. 6 is a broken front elevation of a Abattery of upper godets andtheir drive gear;

rier bar for the lower godets and their associated guides;

Fig. 8 is a section of a. detail of the lower godet drive; and i Fig. 9is a front elevation of a modified layout in which a plurality of uppergodets is used.

It is known that in the` spinning of artificial silk increased tensilestrength of the finished product is attained if the thread, while stillin plastic condition, is placed under tension. To

accomplish this it has been suggested that the thread be interlaced witha series of glass rods submerged in or located adjacent the settingbath,

ter under tension between the rods and the bobbin upon which the'threadis wound. The suggestion has not provedpractical, however, since thedrag of the thread on the rods is' not constant. In actual practicethere is a variation in the frictional engagement of the thread `on ltherods which results in nonuniform tensile strength, inequality of denier,and uneven dyeing properties.

It has also been suggested that the thread be led from a stationaryguide, submerged in the Fig. 7 is a front elevation of an adjustablecarsetting bath, to a positively driven cylinder and thence to a windingbobbin, the peripheral speed of the bobbin exceeding that of thepositively driven cylinder. Practical experience has established,however, that there is not only slippage of the thread at the cylinderwhich prevents uniformity of tension between the latter and the windingbobbin, but also that the deflection of the thread ata sharp angle fromthe submerged .guide to the cylinder is in itself objectionable, sinceit prevents uniformity of tension between, guide and cylinder andbetween guide and spinning nozzle. The frictional engagement of thethread at a guide Aincreases rapidly with the an- 7o gle of deection,and when the angle of deflection is marked the engagement of the threadwith the guide is non-uniform. It must be borne in mind that uniformityof tension is essential to uniformity of strength, denier and dyeingqualities in the finished product, and that a product 4which lacks thesecharacteristics is not acceptable to the trade. So far as I am aware, nomethod has heretofore been suggested by which uniformity oftension onthe thread during the spinning operation has been attained. My inventionprovides a simple and workable method and apparatus for accomplishingthis result by means which are adaptable to standard apparatus withoutundue expense in view of the greatly improved character of the productwhich results from the practice of my invention.

My invention contemplates the engagement of the thread (that is to saythe group of filaments 'which eventually constitutes the thread)between` spaced rotors positively driven at different peripheral speeds,the engagement of the thread with each of the rotors being so effectedthat no appreciable slippage occurs at either. A uniform tension is thusplaced 'on the thread 95 between these rotors, and also between thespinning nozzle and the rotor which draws the thread Vfrom the spinningbath. A the interlacing of the thread with the rods result- 45 ing in adrag on the thread which places the lat- The conditionwhich must beycreated to do away with appreciable slippage is that of substantalidentity betweenv the speed of the rotor and the speed of the portionofthe thread in engagement with the rotor. It is within the scope of theinvention to use other movable elements than rotors to engage thethread. 1 l As will appear from the description following of thepreferred embodiment, it is an underlying thought of this inventionthat, in drawing the thread from the setting bath, as the thread passescertain spaced points or positions in its path of 11 travel, theportions of it which, for the instant, are at these spaced points aregiven respectively different speeds and that the difference of threadspeed between these points is maintained constant as succeeding portionsof thread pass. The result is that all portions of the thread are putunder the same tension.

Various eXpedients are available to effect this result. For example, thethread may be passed between pairs of cooperating rolls which positivelyengage the thread at the nip of each roll pair.

This practice, however, is objectionable from 'several standpoints. Iprefer an arrangement such as indicated in the accompanying drawings, inwhich the engagement of the thread with yeach rotor is effected bylapping the thread thereon to an extent suicient to insure a frictionalgrip of the thread on the rotor which prevents-v appreciable slippageYat that point.

Referring to the drawings, I have illustrated in Fig. 1, more or lessdiagrammatically, a layout which comprises asetting bath 15, into whichthe group of filaments which composes the thread is discharged through asubmerged nozzle 16 connected to the pump 17. From the spinning nozzle16 the thread passes to a guide 18 so arranged with respect to apositively driven lower godet 19 that the thread is delivered Iwithoutsubstantial deflection by the guide 18 to the periphery of the godet. Onthe latter the thread is lapped sufficiently toinsure anon-slipfdraughting engagement therewith, and is taken from the godetover a second guide 20 located to prevent interference between the onand off courses of the thread on the godet. Both guides 18 and 20, aswell as the godet spindle 21, are carried by a bar 22 longitudinallyadjustable on its supporting brackets 23 to vary the length of thethread submersion in the bath 15. The guide 20 is also preferablymounted on an adjustable bracket 24 so that its position with respect tothe godet may be varied.

The thread 25 passes from guide 20 to the upper godet 26, with'which isassociated the guide 27. The notch 28 of the guide 27 receives thethread and delivers it to the godet 26 adjacent the rim flange 29 of thelatter. Lapping the godet 26 the thread is engaged in notch 30 of theguide from which it again laps the godet 26, thus similarly insuring anon-slip draughting engagement between the godet and thread. Passingfrom the godet 26 the thread descends through the guide funnel 31 to acoiling device such as a spinning box (not shown).

Any suitable means may be provided for driving the godets 21 and 26 atdifferentA peripheral speeds. In the layout shown the godets are ofv thesame diameter and the gearing is so arranged as to impart to the godet19 a slower speed of rotation than that imparted to the upper godet 2G.Both take their drive from the main shaft 32. The drive for the lowergodet 19 is indicated in Fig. 4 through bevel gears 33, 34, sprocket 35on the shaft of bevel gear 34 meshing with idler pinion 36 which in turnmeshes with gear 37 on the driving shaft 38 for the pump 1'7.` 'Gear 37drives idlers 39 and 40, the latter meshing with pinion 41 slidablykeyed on shaft 42, which is provided at intervals along its length withbevel gears 43, each meshing with a bevel gear 44 on the vspindle 21 ofa godet 19. The upper godet 26 is driven from shaft 32 throughbevel`pinion 46, meshing with a bevel sprocket 47 on shaft 48, a second bevelsprocket 49 at the opposite end of the shaft meshing with bevel gear 50on shaft 51 of sprocket 52 throughy which motion is transtwo godets 21and 26 may be varied to increase or decrease the tension exerted uponthe thread as it passes therebetween and between the lower godet and thespinning nozzle. Gear 37 may be replaced by a gear of different size ifit is desired tochange proportionally the speedsg of pump 17 and godets19. The adjustable mounting of the idlers 39, 40 and 53 permits thesesubstitutions.

The number of laps necessary to insure a sufficient frictional grip ofthe thread upon the godets may vary with the diameter of the latter,with theirspeed of rotation, the denier of the thread and other factors.It may be desirable under certain conditions to vary the number of lapson either or both godets, and my invention contemplates appropriateguide constructions to prevent interference between the courses ortracks of the laps on the respective godets. Guide 27, as well as guide20, is preferably adjustable upon its support. The guides may be glassor porcelain rods. 'They may be substituted if desired by metallicspindles, upon which small pulleys of glass, or other inert material,may be journaled to prevent possible injury to the thread by frictionalengagement. Guide pins of known type may be used if desired.

When the godets are lapped by the thread in this fashion there is noappreciable slippage of the thread on the godets. Consequently a uniformtension, determined by their relative peripheral speeds, is imparted tothe thread between the godets and between the lower godet and thespinning'nozzle. Thetension thus applied may be so increased withoutdanger of slippage that the tensile strength of the product, both Wetand dry, is greatly increased over that heretofore attained in themanufacture of artificial silk 'speed, thus adding still further to thetension placed upon the thread and further increasing its strength,while maintaining the desired unformity of strength, denier and dyeingproperties.

Of coursegodet 26 or 59 may be replaced by a bobbin, when bobbin windingis desired, suitable means being provided to maintain constant thetension upon the thread between the bobbin and the preceding godet asthe diameter of the bobbin increase.

With the understanding that the apparatus shown is but a-singleillustrative embodiment of apparatus appropriate for carrying out myinvention according to the wet spinning process, and that it may bevaried in many ways to accomplish a like result, in either wet or dryspinning processes, without departing from the thoughts which underliewhat I claim as my invention.

1. In the manufacture of artificial silk from a cellulosic solution, thesteps of drawing the thread .from the spinning nozzle by a driven rotor,leading the thread from said rotor to a second rotor positively drivenat higher peripheral speed, causing the thread to travel atsubstantially the same linear speed, While in association with eachrotor, as'the portion of the said rotor with which the thread isassociated to effect a uniform stretching effort upon the thread betweenthe rotors and delivering the thread continuously from said secondrotor.

2. In the manufacture of artificial silk from a cellulosic solution, thesteps of stretching the thread While in plastic condition by lapping itupon spaced rotors having different peripheral speeds, the lappage beingsunicient to cause the thread to have, at each rotor, substantially thesame lineal` speed as the periphery of the rotor and delivering thethread continuously from the last of said rotors.

3. In the manufacture of artificial silk from a cellulosic solution, thesteps of stretching the thread while in plastic condition, by lapping itupon spaced rotors having different peripheral speeds, the lappage beingsufiicient to cause the thread, at each rotor, to have substantially theIsame linear speed as the periphery of Ithe rotor and guiding the threadon each rotor to prevent the thread from tracking on itself.

4. In the manufacture of artificial silk from a cellulosic solution, themethod ofstretchingthe thread which-comprises feeding the thread from`the spinning nozzle into engagement with a series of rotors whilecausing the thread engaging portion of each rotor to have a higherlinear speed than the corresponding portion of the preceding rotor inthe series and While causing the thread to have, at each rotor,substantially the same linear speed as the portion of the rotor itengages, and delivering'the thread continuously from the last of saidrotors. l

5. In the manufacture of artificial silk from cellulosic solution, themethod of giving the thread uniform tension While drawing it from thesetting bath which consists in giving the thread a, different linearspeed at predetermined spaced points in its path of travel andmaintaining this difference of speed constant for succeeding portionsofthe thread passing these points.

6. In the manufacture of artificial silk from a cellulosic solution, thelmethod of passing the thread from thespinning nozzle to a coilingdevice, which comprises drawing the thread from the spinning nozzle by adriven godet, delivering the thread from said godet to a second godetdriven at a higher peripheral speed, causing the thread While vinengagement with each godet to have substantially the same linear speedas the portion of the godet that it engages, and delivering the threadcontinuously from said godets to a coiling device.

7. In the manufacture of artificial silk from a cellulosic solution, themethod of passing the thread from the spinning nozzle to a coilingdevice which comprises drawing the thread from the spinning nozzle by adriven rotor, delivering the thread from said rotor to a second rotordriven at higher peripheral speed, causing the thread while inengagement with each rotor to have the same -linear speed as the portionof the rotor which it engages, and delivering the thread continuouslyfrom said second rotor to a coiling device.

8. In the manufacture of artificial cellulosic silk, the method ofdelivering the thread from the spinning nozzle to a coiling means whichcomprises giving the thread a different speed at spaced points in itspath of travel thespeed at each pointibeing higher than at the precedingpoint, and maintaining the respective speeds constant for successiveportions of the thread passing said points.

9. Apparatus for the manufacture of artificial silk comprising a pairlof spaced rotors positively driven at different. peripheral speeds, andmeans associated with each'rotor for thereon engaging against slippageand trackage a thread drawn by the rotor of higher peripheral speed fromthe rotor of lower peripheral speed.

l0. Apparatus for the manufacture of artificial silk comprising aspinning bath, a positively driven rotor in proximity to the bath, andmeans associated with the rotor for thereon engaging against slippage athread drawn by the rotor from the bath, in combination with a similarrotor of higher peripheral speed, and means for thereon engaging againstslippage the thread drawn thereby under tension from the first rotor.

11. Apparatus for the manufacture of artificial silk comprising a pairof spaced godets, means for positively driving said godets at differentperipheral speeds, and guide means associated with each godet forpreventing trackage interference thereon of a thread extending betweensaid godets and lapped on Veach to prevent slippage of the thread onsaid godets due to the tension exerted on the thread by the draft of thegodet having higher peripheral speed.

12. An artificial silkproducing apparatus having a spinning nozzle fordelivering thread-formingmaterial to a setting bath and a means forcoiling the thread, in combination with two or more godets between thenozzle and the coiling means, said godets having means for guiding thethread therearound with an arc of contact of the yarn on the godetssufcient to prevent slippage,

and means for driving the godets each at a uniform peripheral speedhigher than that of the preceding godet, for the purpose set forth.

13. Apparatus forstretching freshly spun filaments of articial silk,comprising a spinning nozzle, two or more rollers spaced apart, eachroller revolving at a peripheral speed greater than the peripheral speedof the preceding roller, in combination with means. associated with eachroller for guiding the thread onto the same, and a second thread guidingmeans for preventing tracking of the thread inserted in the threadcourse at veach roller positioned to move the thread from one positionon the roller to another as the thread passes one or more times aroundthe respective rollers.

. 14. Apparatus for the manufacture of artificial silk thread,comprising a spinning nozzle, a pair of spaced godets around which thethread is lapped to prevent slippage, and means for driving said godetspositively at different peripheral speeds, in combination with guidemeans associated with a godet adapted to contact with thread as itpasses around said lapped godets to prevent trackage thereon.

15. Apparatus for the 'manufacture of artificial silk thread, comprisinga pair of spaced godets driven at different peripheral speeds, eachadapted to have arcs of contact with the thread sufficient to ensureagainst slippage of the thread on the godets, in combination with aguide means at each godet guiding the thread onto same, and

`a second guide means positioned to remove the thread from the godetafter the thread has contacted with` the godet and to guide it!` backonto cial silk, comprising a pair of spaced god "Q means for positivelydriving said godets L. different peripheral speeds and guide meansassociated with each godet having a plurality of guiding surfaces, onesuch surface being located and adapted to guide the thread onto thegodet in the rst instance, and the other guiding surfaces being adaptedto remove the thread from the` godet and place it back on the godet soas to prevent tracking by placing it at a different position from thatgiven by each of the other guiding surfaces.

17. In the manufacture of artificial silk from

